The present invention relates to a developer storage body, an image forming unit and an image forming apparatus.
Generally, an image forming apparatus using electrophotography, such as a printer, a facsimile machine or a copier, includes an image forming unit, an LED head, a transfer roller, a fixing unit and the like. The image forming unit includes a photosensitive drum, a charging roller, a developing unit, a cleaning roller and the like. The charging roller uniformly charges a surface of the photosensitive drum, and the LED head emits light to expose the surface of the photosensitive drum according to image data so as to form a latent image. The developing unit develops the latent image to form a toner image. The transfer roller transfers the toner image to a sheet as a printing medium. The fixing unit fixes the toner image to the sheet.
The image forming unit includes an image forming unit main body and a toner cartridge (i.e., a developer storage body) detachably mounted to the image forming unit main body. The toner cartridge includes an outer case in which a toner as a developer is stored, and an inner case rotatably provided in the outer case. The outer case has a toner supply opening through which the toner is supplied to the image forming unit main body. The inner case has a shutter part for opening and closing the toner supply opening (see, for example, Japanese Laid-Open Patent Publication No. 2001-42620).
Recently, there is a demand for a developer storage body capable of sufficiently supplying a developer to an image forming unit main body.